JP6074096B1 - Sheet profile control method for hot finishing tandem rolling mill and hot finishing tandem rolling mill - Google Patents

Abstract

An edge profile can be controlled to a predetermined value or less, and a plate crown is controlled to a predetermined value or less within a permissible range. In a decision control device 60 of a control system 50, a plate crown and an edge on the outlet side of the final stand 100 with respect to a line load and a plate shape control parameter obtained for a final stand 100 of a hot finish tandem rolling mill 1. Based on the profile relationship, the line load of the final stand 100 is adjusted so that the edge profile is within the allowable range so that the plate shape on the exit side of the final stand 100 is within the allowable range and the plate crown is less than the predetermined value. A predetermined pass schedule is determined by adjusting the plate shape control parameters of the final stand 100. [Selection] FIG.

Description

  The present invention relates to a plate profile control method for a hot finishing tandem rolling mill and a hot finishing tandem rolling mill.

  As a means for reducing edge drop, which is a rapid reduction in sheet thickness in the vicinity of the sheet width end portion in a hot finishing tandem rolling mill, as disclosed in Patent Document 1, tension in the rolling direction at the latter stage of the finishing mill is pulled. There is a method of reducing the edge drop while satisfying the target plate crown by reducing the edge load due to roll flattening by reducing the rolling load in the vicinity of the end of the width of the rolled material plate. .

  Patent Document 2 describes that a rolling mill having a roll shift mechanism is installed at the final stand of a hot finishing tandem rolling mill as equipment for suppressing edge-up caused by roll thermal and wear.

JP-A-5-237527 JP 61-108405 A

  Usually, in a hot finish rolling mill, the work roll is worn by an increase in the number of rolling coils. In particular, an edge-up phenomenon in which the plate thickness becomes thick at the plate width end portion is caused by local wear at the plate width end portion and thermal crown generated by thermal expansion of the work roll portion.

  In the technique described in Patent Document 1 described above, the plate crown can be set to a predetermined value. Along with this, it is possible to reduce edge drop caused by roll flattening. However, the technique described in Patent Document 1 has a problem that both the plate crown and the edge drop cannot be set to a predetermined value or less. The same is true for edge-up. In particular, it is necessary to suppress the edge-up as much as possible because the edge-up can not only make a desired plate profile but also cause a deterioration of the sheet passing property.

  Further, the plate profile preset control model in the hot rolling described in Patent Document 1 described above is a model that controls only the plate crown defined at a predetermined position to a predetermined value or less. In this model, the plate crown and the edge profile are controlled. There was a problem that it was very difficult to control both below a predetermined value.

  Therefore, the present invention solves the above-mentioned problems in the prior art, can control the edge profile to a predetermined value or less, and can control the plate crown to a predetermined value or less within the allowable range. It is an object of the present invention to provide a plate profile control method for a hot finishing tandem rolling mill and a hot finishing tandem rolling mill.

In order to achieve the above object, according to a first aspect of the present invention, in the sheet profile control method for a hot finishing tandem rolling mill having a plurality of stands, the linear load obtained for the final stand of the hot finishing tandem rolling mill And adjusting the line load of the final stand so that the edge up or edge drop falls within an allowable range based on the relationship between the plate crown and the edge up or edge drop on the final stand exit side with respect to the flatness control parameter, The flatness control parameters of the final stand are adjusted so that the flatness on the exit side of the final stand is within an allowable range and the plate crown is equal to or less than a predetermined value, and the adjusted line load and flatness control of the final stand are performed. The pass schedule of the final stand is adjusted based on the parameters.

The second aspect, in the first aspect, or flatness in the final stand delivery side only by adjusting the flatness control parameter of the last stand is not a permissible range, the plate at the final stand delivery side If the crown does not fall below the predetermined value, the upstream stand is flattened so that the flatness at the final stand is within the allowable range and the plate crown is below the predetermined value sequentially from the final stand toward the upstream side. The degree control parameter is adjusted.

According to a third aspect, in the first aspect, a reduction amount of the final stand that achieves a linear load at the final stand is obtained, and the reduction is performed so that the flatness is within an allowable range based on the reduction amount. It is characterized by determining a schedule.

  The fourth invention is characterized in that, in the first invention, the work roll of the final stand is polished while rolling at each stand using the pass schedule.

Further, the fifth invention is based on the relationship between the plate crown and the edge up or edge drop on the final stand exit side with respect to the existing pass schedule of the hot finish tandem rolling mill in the first invention. The line load of the final stand is adjusted, and the flatness control parameter of the final stand is adjusted for an intermediate path schedule in which the line load of the existing path schedule is adjusted.

According to a sixth aspect, in the first aspect, the flatness control parameter of the final stand is a work roll bending force, a roll cross angle, and a roll shift amount of the work roll bender.

In order to achieve the above object, according to a seventh aspect of the present invention, in a hot finishing tandem rolling mill having a plurality of stands, a reduction device and a plate shape control actuator provided in each of the plurality of stands, A determination control device that determines a pass schedule; and a rolling mill control device that controls the reduction device and the plate shape control actuator based on the predetermined pass schedule determined by the determination control device. , the obtained for the final stand of the hot finish tandem rolling mill, based on the relationship of the strip crown and edge-up or edge drop in the final stand delivery side for the line load and the flatness control parameter, said edge up or edge drop adjusts the line load of the final stand so that the allowable range, the final Stand out flatness in side becomes within the permissible range and the plate crown is what determines the predetermined pass schedule by adjusting the flatness control parameter of the last stand to be equal to or less than a predetermined value, the rolling The machine control device controls the reduction device to obtain the adjusted line load of the final stand, and controls the plate shape control actuator to obtain the adjusted flatness control parameter of the final stand. To do.

In addition, in an eighth aspect based on the seventh aspect, the determination control device, on determining the predetermined pass schedule, only adjusts the flatness control parameter of the final stand, and determines the final stand on the exit side of the final stand. If the flatness is not within the allowable range, or the plate crown on the final stand exit side is not less than the predetermined value, the flatness at the final stand is sequentially within the allowable range from the final stand to the upstream side. The flatness control parameter of the upstream stand is adjusted so that the inner plate crown is equal to or less than a predetermined value.

Further, in a ninth aspect based on the seventh aspect, the determination control device obtains a reduction amount of the final stand that realizes a line load at the final stand when determining the predetermined pass schedule, The reduction schedule is determined so that the flatness is within the allowable range based on the amount of reduction.

  Further, a tenth aspect of the invention is the seventh aspect of the invention, further comprising a roll polishing device, wherein the rolling mill control device performs rolling at each of the plurality of stands based on the predetermined pass schedule and the roll polishing. The reduction device, the plate shape control actuator, and the roll polishing device are controlled so as to polish the work roll of the final stand by an apparatus.

  According to the first and seventh aspects, the edge profile on the final stand exit side can be controlled to a predetermined value or less, and the plate shape can be controlled to a predetermined value or less with a plate crown within an allowable range, which is good. A board profile can be obtained.

  Further, according to the second and eighth inventions, not only can the edge profile be controlled more reliably below the predetermined value, but also the plate shape can be controlled within the allowable range, and the plate crown can be controlled below the predetermined value. it can.

  In addition, according to the third and ninth inventions, a constant plate crown ratio on each stand exit side can be realized, so that the plate shape is also improved, and a better plate profile can be provided.

  Further, according to the fourth and tenth inventions, rolling is performed while the surface shape of the work roll is improved, so that the edge profile at the final stand exit side can be controlled to a predetermined value more easily. Therefore, the control range of each parameter including the line load at the final stand is widened, and the operation becomes easier.

  Further, according to the fifth invention, not only the edge profile can be controlled stably and reliably to a predetermined value or less, but also the plate shape can be controlled to a predetermined value or less within the allowable range and the plate crown.

  According to the sixth aspect of the invention, the work roll bender, the roll cross angle, and the roll shift amount are changed during rolling, and a good plate profile can be obtained more easily.

It is the figure which showed the last stand and plate | board profile of a hot finishing tandem rolling mill. It is a figure explaining the principle of the roll profile by the thermal crown and wear crown of the work roll part of a hot finishing tandem rolling mill. BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the outline of the hot finishing tandem rolling mill of Example 1. FIG. It is a figure which shows the definition of the sheet | seat crown in the hot finishing tandem rolling mill, edge drop, and edge up. It is a figure which shows the inheritance of the edge drop in the last stand of a hot finishing tandem rolling mill. It is a figure which shows the sheet | seat crown heritability in the last stand of a hot finishing tandem rolling mill. It is a figure which shows the calculation result of each stand exit side board profile on the conditions shown in Table 2 in Example 1 of this invention. It is a figure which shows the setting of the thermal crown and wear crown of each stand work roll in Table 2. It is a figure which shows the calculation result of the thermal crown of the last stand, a wear crown, and work roll flat distribution. It is a figure which shows the relationship between the thermal crown of the last stand, a wear crown, and work roll flat distribution. It is a figure which shows the calculation result of the thermal crown, wear crown, and work roll flat distribution on the conditions which set to 12.9 kN / mm in the final stand shown in Table 3 of Example 1. FIG. It is a figure which shows the calculation result of each stand exit side board profile on the conditions which set the line load to 12.9 kN / mm in the last stand shown in Table 3 of Example 1. FIG. In Example 1, it is a figure which shows the relationship between the plate crown and edge profile for every line load in the last stand. It is a figure which shows an example of the board profile control by the line load up of the last stand in Example 1, and work roll bending force adjustment. It is a figure which shows the change of the steepness by the linear load up of the last stand in Example 1, and work roll bending force adjustment. It is a figure which shows the change of the plate crown by the line load increase of the last stand in Example 1, and work roll bending force adjustment. It is a figure which shows an example of the change of the board profile before changing the bending force by the side of the last stand by the board profile control in Example 1. FIG. It is a figure which shows an example of the change of the board profile after changing the bending force by the side of the last stand by the board profile control in Example 1. FIG. It is a figure which shows an example of the rolling-down schedule in each stand according to the line load in the last stand in Example 1. FIG. In Example 1, it is a figure which shows the target value of the exit side plate crown of each stand in the case of the linear load 12.9kN / mm in the last stand. It is a figure which shows the plate crown ratio schedule in Example 1 by the line load 12.9kN / mm in the last stand. It is a figure which shows the control flow of the board profile in Example 1. FIG. It is a figure which shows the outline of the hot finishing tandem rolling mill of Example 2 of this invention. It is a figure which shows the setting of the thermal crown and wear crown of each stand work roll in Table 5. In Example 2, it is a figure which shows an example of each stand exit side plate profile in the thermal & abrasion crown unconditional in the last stand shown in Table 5. FIG.

  First, the plate profile in the present invention is a plate thickness distribution in the plate width direction, and is classified into a plate center portion and a plate edge portion. The plate crown defined by the plate thickness difference between the plate center and the plate center / edge division position, and the edge defined by the plate thickness difference between the plate center / edge division position and the plate edge position at the plate edge portion It consists of up or edge drop.

The plate shape means the flatness of the plate, and the flatness includes end extension and middle extension. There is also a steepness obtained by dividing the wave height of the plate by the pitch of the wave of the plate. Flatness and plate crown are related, and flatness is obtained by multiplying the change in plate crown ratio on the exit side and entry side of the stand by the shape change coefficient determined by the work roll diameter, plate width, plate thickness, etc. It becomes. The plate shape described below is flatness.

  Next, the background of the present invention will be described below.

  As shown in FIG. 1, the plate profile of the rolled material has different characteristics between the plate center region and the plate end region, and the plate profile changes abruptly at the plate end.

  Here, the center crown of the plate, that is, the plate crown is affected by roll deflection during rolling. Edge drop or edge up in the plate edge region is greatly affected by metal flow and roll flatness in the vicinity of the plate width end.

  Therefore, in order to control the sheet crown of the rolled material to a desired profile over the entire sheet width direction, the edge drop or edge up is controlled to a predetermined value or less, and the sheet shape is within an allowable range. Needs to be controlled to be equal to or less than a predetermined value.

  Generally, edge drop or edge up in hot rolling is influenced by the operating conditions of the stand alone, and the influence of the upstream stand is small. In other words, edge drop or edge up is said to have low heritability, but none has been quantitatively evaluated.

  Moreover, when the number of rolling increases, roll wear increases as shown in FIG. In particular, edge-up occurs at the end portion of the plate width due to local wear at the end portion of the plate width and thermal crown due to thermal expansion of the roll.

  Since the heritability of edge drop or edge up is considered to be small as described above, edge drop or edge up can be suppressed by changing the operating conditions of the final stand.

  In addition, normally, the final stand is operated with a low rolling reduction. When the line load is reduced, the roll flat deformation in the vicinity of the end of the plate width is reduced. For this reason, if an operation method with a small rolling reduction is used, the plate crown can be set to a predetermined value within the allowable range, but the effect of suppressing edge-up caused by roll thermal and wear at the final stand is reduced. The edge profile cannot be controlled to a predetermined value.

Therefore, in the present invention, the above relationship is preferably obtained in advance based on the relationship between the plate crown and the edge drop or edge up on the final stand exit side, and the line load at the final stand is controlled by controlling the reduction device. was adjusted by manipulating the plate-shaped control actuator in the final stand of the hot finish tandem rolling mill, the strip shape is within the allowable range, and a control for adjusting so that the strip crown than a predetermined value. By this method, the plate crown and the edge profile can be adjusted to be equal to or less than a predetermined value, and a good plate profile can be obtained.

Further, the plate-shaped braking tolerance only a plate shape control actuator in the final stand, and if the plate crown is not easy to control below a predetermined value, while giving priority to the plate shape in order from the finish rear stage given It was set as the method of adjusting so that it might become a board crown.

  Furthermore, the work roll polishing device is arranged to improve the roll surface of the work roll of the final stand so that the plate shape can be easily adjusted within the allowable range and the plate crown can be adjusted to a predetermined value or less.

  Examples of the plate profile control method for a hot finishing tandem rolling mill and the hot finishing tandem rolling mill of the present invention based on the above examination will be described below with reference to the drawings.

<Example 1>
A plate profile control method for a hot finishing tandem rolling mill and a hot finishing tandem rolling mill according to a first embodiment of the present invention will be described with reference to FIGS. First, the hot finish tandem rolling mill 1 will be described with reference to FIG. FIG. 3 is a diagram showing an outline of a hot finishing tandem rolling mill.

  As shown in FIG. 3, the hot finish tandem rolling mill 1 is a rolling mill that hot-rolls the hot-rolled material 110 into a strip, and includes an F1 stand 10, an F2 stand 20, an F3 stand 30, an F4 stand 40, 5 stands of F5 stand 100 and a control system 50 are provided. Note that the hot finishing tandem rolling mill 1 is not limited to five stands as shown in FIG.

  The F1 stand 10 includes a pair of upper and lower work rolls 12 and 12, a pair of upper and lower backup rolls 13 and 13, a pair of upper and lower work roll benders 14 and 14, and a reduction device 15. The F2 stand 20 includes a pair of upper and lower work rolls 22 and 22, a pair of upper and lower backup rolls 23 and 23, a pair of upper and lower work roll benders 24 and 24, and a reduction device 25. The F3 stand 30 includes a pair of upper and lower work rolls 32, 32, a pair of upper and lower backup rolls 33, 33, a pair of upper and lower work roll benders 34, 34, and a reduction device 35. The F4 stand 40 includes a pair of upper and lower work rolls 42 and 42, a pair of upper and lower backup rolls 43 and 43, a pair of upper and lower work roll benders 44 and 44, and a reduction device 35. The F5 stand 100 as the final stand includes a pair of upper and lower work rolls 120 and 120, a pair of upper and lower backup rolls 130 and 130, a pair of upper and lower work roll benders 140 and 140, and a reduction device 150.

  The work rolls 12, 22, 32, 42 and 120 roll the hot rolled material 110. The backup rolls 13, 23, 33, 43, and 130 support the corresponding work rolls 12, 22, 32, 42, and 120, respectively.

  Further, the upper work rolls 12, 22, 32, 42, 120 and the backup rolls 13, 23, 33, 43, 130, and the lower work rolls 12, 22, 32, 42, 120 and the backup roll 13 are provided. , 23, 33, 43, and 130 are pair cross rolls that can cross each other in a horizontal plane.

  The work roll benders (plate shape control actuators) 14, 24, 34, 44, 140 are devices for applying bending force to the work rolls 12, 22, 32, 42, 120, and change the bending force. Thus, the cross-sectional shape of the hot-rolled material 110, particularly the plate crown and flatness can be corrected.

  The reduction devices 15, 25, 35, 45, and 150 are devices that individually apply a reduction force to the corresponding backup rolls 13, 23, 33, 43, and 130.

The control system 50 includes a determination control device 60 that determines a predetermined pass schedule, a reduction device 15, 25, 35, 45, 150 and a work roll vendor 14, based on the predetermined pass schedule determined by the determination control device 60. 24, 34, 44, 140, a rolling mill control device 70 for controlling a cross angle changing actuator (not shown), and a linear load and flatness control parameter ( preliminarily determined for the final stand 100 of the hot finish tandem rolling mill 1 ) Hereinafter, the storage unit 80 stores the relationship between the plate crown and the edge profile on the exit side of the final stand 100 with respect to the plate shape control parameter.

  Here, in this embodiment, the shape control actuator of the final stand 100 is the work roll bender 140, and the plate shape control parameter is the work roll bending force of the work roll bender 140.

  The shape control actuator of the final stand 100 may be a cross angle change actuator, and the plate shape control parameter may be a roll cross angle. Further, the shape control actuator of the final stand 100 may be a roll shift actuator, and the plate shape control parameter may be the roll shift amount. Furthermore, the shape control actuator of the final stand 100 can be a work roll bender 140 and a cross angle changing actuator or a roll shift actuator, and the plate shape control parameter can be a work roll bending force and a roll cross angle or a roll shift amount. .

  The determination control device 60 is provided on the outlet side of the final stand 100 for the line load and the work roll bending force of the work roll bender 140 stored in the storage unit 80 with respect to the existing pass schedule of the hot finish tandem rolling mill 1. Based on the relationship between the plate crown and the edge profile, the intermediate path schedule is determined by adjusting the line load of the final stand 100 so that the edge profile falls within the allowable range. Further, the work roll bending force of the work roll bender 140 is adjusted so that the plate shape on the exit side of the final stand 100 is within an allowable range and the plate crown is equal to or less than a predetermined value with respect to the intermediate pass schedule. Then, based on the adjusted line load of the final stand 100 and the work roll bending force of the work roll bender 140, a pass schedule (predetermined pass schedule) of a plurality of stands (F1 stand 10 to F5 stand 100) is determined.

  In particular, when determining the predetermined pass schedule, the determination control device 60 determines whether the plate shape on the exit side of the final stand 100 is within the allowable range only by adjusting the work roll bending force of the work roll vendor 140 of the final stand 100. When it is determined that the plate crown does not fall below the predetermined value, the plate shape at the final stand 100 is within the allowable range in order from the final stand 100 side to the upstream side, so that the plate crown falls below the predetermined value. The work roll bending force of the work roll benders 14, 24, 34, 44 of the upstream side stand (F1 stand 10 to F4 stand 40) is adjusted.

  Further, when determining the predetermined pass schedule, the determination control device 60 obtains a reduction amount of the final stand 100 that realizes a linear load on the final stand 100, and the plate shape is within the allowable range based on the reduction amount. Determine the reduction schedule to be

  The rolling mill control device 70 controls the reduction devices 15, 25, 35, 45, and 150 of each stand so that the adjusted line load of the final stand 100 is obtained, and the adjusted plate shape control parameters of the final stand 100 are obtained. The work roll vendors 14, 24, 34, 44, 140 of each stand are controlled.

  Next, in the determination control device 60, the relationship between the plate crown and the edge profile on the exit side of the final stand 100 with respect to the line load and the work roll bending force of the work roll bender 140 used to determine a predetermined pass schedule, and the edge A method of adjusting the line load of the final stand 100 so that the profile is within the allowable range, and the work roll of the final stand 100 so that the plate shape on the exit side of the final stand 100 is within the allowable range and the plate crown is equal to or less than a predetermined value. An example of a method for adjusting the work roll bending force of the vendor 140 will be described below.

  First, the results of the study by the present inventors regarding edge drop genetic characteristics will be described.

  First, the plate profile in the hot finish tandem rolling mill was calculated using the finite element method, and the relationship between the amount of entry edge drop and the amount of exit edge drop was arranged. Table 1 shows the calculation conditions, and FIG. 5 shows the results.

As shown in Table 1, the work roll was 680 mm in diameter, the backup roll was 1450 mm in diameter, the plate width was 1577 mm, and the finished plate thickness was 4.88 mm. In the calculation, the work roll profiles of thermal crown-37.5 μm / rad and wear crown-25 μm / rad were considered.

  Here, the thermal crown is a phenomenon in which the work roll thermally expands due to contact with the plate, and is a condition in which the diameter of the work roll increases by about 37.5 μm per radius from the end of the plate to 100 mm. It was defined as the deviation from the center of the plate. The wear crown is a phenomenon of local wear at the end of the plate due to contact with the plate, and is defined as a condition where the diameter of the work roll becomes smaller by about 25 μm per radius at the end of the plate, and here defined as a deviation from the center of the plate. .

  Further, as shown in FIG. 4, the detailed definition of the plate crown is the difference (Ch100) between the plate thickness at the plate end 100 mm position and the plate thickness at the plate center. The detailed definition of edge drop or edge up is to estimate the plate thickness (plate thickness 25 mm, he ′) at the plate end 25 mm position by polynomial approximation from the plate thickness distribution from the plate center to the plate end 100 mm. Edge drop or edge up was evaluated as the difference from the plate thickness (he) at the plate edge of 25 mm. It should be noted that when the plate thickness at the plate end position of 100 mm is thicker than the plate thickness at the plate end position of 25 mm, the edge up is acceptable.

  As shown in FIG. 5, as a result of arranging the relationship between the entry side edge drop and the exit side edge drop of the final stand 100, it was found that the two are in a linear relationship. It was also found that the heritability of the edge drop, which is the gradient, was as small as 0.17. That is, even if the incoming edge drop changes, only 17% of the incoming edge drop affects the outgoing edge drop. From this, it was quantitatively found that the edge up or edge drop characteristics are almost determined only by the stand.

  The relationship between the entrance side plate crown and the exit side plate crown of the final stand 100 was also organized. The result is shown in FIG. As shown in FIG. 6, the two have a linear relationship, and the heritability of the plate crown, which is the gradient, is 0.56, which is different from the relationship between the entry edge drop and the exit edge drop of the final stand 100. I found it big. That is, it was found that 56% of the incoming plate crown affects the outgoing plate crown.

  Next, the calculation of the rolled steel sheet profile in the hot finish tandem rolling mill 1 under the conditions considering only the thermal crown and the wear crown was performed. The conditions for this calculation are shown in Table 2, and the results are shown in FIG. Table 2 shows the conditions under which the line load at the final stand 100 is 6.7 kN / mm, which is defined as tandem rolling calculation condition 1 (corresponding to an existing pass schedule).

As for the thermal crown, wear crown, and initial crown of the work rolls 12, 22, 32, 42, and 120 of the F1 stand 10 to F5 stand 100, as shown in FIG. 8, the thermal crown is −37.5 μm / rad (plate end). 100 mm), a wear crown of −25 μm / rad (plate end 60 mm), and an initial crown of −140 μm / rad were considered.

  As shown in FIG. 7, it was found that the rolled steel sheet profile was affected by local wear according to the thermal crown and the wear crown as it approached the latter stage, resulting in edge-up in the vicinity of the plate width end.

  FIG. 9 shows the calculation results of the thermal crown, wear crown, and work roll flatness distribution at the final stand. Here, the roll flat distribution is a distribution in the plate width direction of the roll surface flat amount when the load distribution from the plate acts on the work roll 120, as shown in the lowermost stage of FIG. Defined as the deviation from For reference, an outline of a thermal crown and a wear crown is also shown in FIG.

  As shown in FIG. 9, although the total of the thermal crown and the wear crown changes rapidly at the end of the plate width, the roll flattening amount changes more slowly than that, resulting in an edge-up. It was.

  Based on this result, in order to suppress edge-up, calculation of the rolled steel sheet profile in the hot finish tandem rolling mill 1 when the rolling reduction of the final stand 100 is increased and the line load is increased to 12.9 kN / mm. Went. The calculation conditions are shown in Table 3, and the results are shown in FIGS. Table 3 shows the conditions under which the line load at the final stand 100 is 12.9 kN / mm, which is defined as tandem rolling calculation condition 2 (intermediate pass schedule).

In Table 3, the pass schedule is the same as the tandem rolling calculation condition 1 shown in Table 2 for the entry side plate thickness and the finish plate thickness in the hot finishing tandem rolling mill 1 as a whole, and the rolling reduction at the final stand 100 is set to the linear load 12 The thickness of each stand exit side excluding the final stand 100 was adjusted so that the plate shape was in the vicinity of a reduction ratio of 30% within a predetermined range.

  As shown in FIG. 11, when the load per unit width of the final stand 100 is increased to 12.9 kN / mm, the amount of roll flatness near the end of the plate width changes rapidly with respect to the thermal crown and wear crown. I understood. Also, for this reason, as shown in FIG. 12, it was found that edge up at the final stand 100 can be suppressed, resulting in edge drop.

Based on these results, the relationship between the plate crown at the plate end 100 mm position at the final stand 100 and the edge drop or edge up at the plate end 25 mm position, the line load at the final stand 100 is 6.7 kN / mm, the two conditions of 12.9kN / mm, in the conditions of each line load is obtained by changing the setting of the work roll bender 140 is a plate-shaped control actuator in the final stand 100, and arranged as shown in FIG. 13.

  As shown in FIG. 13, it was found that when the bending force by the work roll bender 140 at the final stand 100 is increased, the plate crown is reduced, and when the bending force by the work roll bender 140 is decreased, the plate crown is increased. Further, it was found that when the line load at the final stand 100 is increased, the edge-up is reduced, and when the bending force applied by the work roll bender 140 is weakened to increase the plate crown, the edge-up is reduced.

  Assuming that the target value of the plate crown on the exit side of the final stand 100 is 0.055 mm as shown in FIG. 13, at the line load of 6.7 kN / mm at the final stand 100, the work roll is set to keep the plate crown below a predetermined value. It can be seen that there is no condition that can suppress edge-up within an allowable range even if the vendor 140 is changed.

  Therefore, it is necessary to increase the line load of the final stand 100 in order to make the edge up within the allowable range. For example, to make the edge up 0, the line load in the final stand 100 is increased to 12.9 kN / mm. I found it necessary.

  In this way, the relationship between the plate crown and the edge drop or the edge up at the final stand 100 with respect to the line load and the work roll bending force of the work roll bender 140 is obtained in advance, and the necessary final stand 100 is determined from the predetermined plate crown. It was found that the edge profile is easily and reliably within the allowable range, the plate shape on the exit side of the final stand 100 is within the allowable range, and the plate crown can be reduced to a predetermined value or less.

  FIG. 14 shows the relationship between the plate crown at the plate end 100 mm and the edge profile at the plate end 25 mm when the line load at the final stand 100 is increased from 6.7 kN / mm to 12.9 kN / mm. The bending force at the work roll 120 in F5) and the steepness that is the plate shape at the final stand 100 (expressed as a ratio of the pitch L to the wave height H at the plate end in the rolling direction of the rolled material) and FIG. 15 shows the relationship between the work roll bender 140 of the final stand 100 and the plate crown at the plate end 100 mm.

  With the bending force fixed at 902 kN / chock, the line load at the final stand 100 is increased from 6.7 kN / mm to 12.9 kN / mm (corresponding to (1) in FIGS. 14, 15, and 16). And as shown in FIG. 16, the plate crown becomes large, and as shown in FIG. 15, the steepness tends to be elongated.

  When the predetermined value of the plate crown is 0.055 mm or less and the restriction of the steepness is within ± 0.5%, both results are deviated from the predetermined value, and adjustment by the work roll bender 140 which is a plate shape control actuator is necessary. Become.

  Specifically, since the plate crown is larger than a predetermined value, it is necessary to change the work roll bending force by the work roll bender 140 in the F5 stand 100 to the increase side. Therefore, the work roll bending force of the F5 stand 100 is increased from 902 kN / chock to 1176 kN / chock (corresponding to (2) in FIGS. 14, 15, and 16). This change makes it possible to limit the steepness to about + 0.5% and to reduce the plate crown to 0.055 mm or less, so that the plate shape can be controlled to a predetermined plate crown within a predetermined range. I understand that. Table 4 shows the calculation conditions at this time. This Table 4 is after line load increase + work roll bending force adjustment, and is defined as tandem rolling calculation condition 3 (corresponding to the final pass schedule).

In FIG. 17, when the line load in tandem rolling calculation condition 3 is increased from 6.7 kN / mm to 12.9 kN / mm (corresponding to (1) in FIGS. 14, 15, and 16), The plate profile calculation result is shown in FIG. 18, and the final stand when the work roll bender 140 in the final stand 100 under the tandem rolling calculation condition 3 is adjusted to the incremental side (corresponding to (2) in FIGS. 14, 15, and 16). The plate profile calculation result at 100 outlets is shown.

  As shown in FIG. 17, it was found that the plate crown of the exit profile of the final stand 100 is increased by increasing the line load. Further, as shown in FIG. 18, it was found that the plate crown at the plate end 100 mm position can be controlled to the same value by adjusting the work roll bender 140 to the increase side. At this time, it was also found that the edge-up amount was small.

  Next, an example of a method of determining a predetermined pass schedule in the determination control device 60 when the plate shape is within an allowable range and the plate crown cannot be set to a predetermined value only by the work roll vendor 140 at the final stand 100. This will be described below.

  Depending on the rolling conditions, the edge profile becomes acceptable only by adjusting the line load of the final stand 100 and the work roll bending force of the work roll bender 140 of the final stand 100, and the plate shape on the exit side of the final stand 100 is acceptable. In some cases, it may be difficult to set the crown to a predetermined value or less. In such a case, the determination control device 60 also adjusts the work roll vendors 14, 24, 34, and 44 in order from the subsequent stage side, changes the entry side plate profile, and creates a predetermined pass schedule.

As described above, the plate crown can be controlled to a predetermined value in the conventional method. However, the sheet crown has a constant sheet crown ratio (defined by the ratio of the center thickness (H) of the rolled material before rolling to the crown (C _H ) (C _H / H)) by rolling in the middle elongation direction. I can't. On the other hand, in this embodiment, the target plate crown can be satisfied by adjusting the work roll bender 140 with respect to the plate shape and the plate crown which are shifted due to the line load adjustment of the final stand 100.

  Further, if the line load of the final stand 100 is adjusted in order to satisfy the certain condition of the plate crown ratio, the reduction schedule needs to be corrected.

  Specifically, as shown in FIG. 19, the inlet side plate thickness and the final outlet side target plate thickness of the rolling mill are fixed, and a reduction amount that becomes a necessary line load of the final stand 100 is set using a preset deformation resistance. As shown in FIG. 20, the work roll bender 140 is adjusted so that the plate shape is within the allowable range and becomes a predetermined plate crown.

  As shown in FIG. 21, it is only necessary to achieve a constant plate crown ratio on the exit side of all the stands. However, if the constant plate crown ratio cannot be achieved, the amount of reduction of the upstream stand is corrected, and the work roll bender 140 is adjusted. The plate crown ratio is made constant on the upstream side, and the work is performed in order from the rear side toward the upstream stand until the reduction schedule satisfies the plate crown ratio in all the stands. , 45 and the work roll bending force by the work roll vendors 14, 24, 34, 44 are corrected.

  FIG. 22 shows a control flow for determining a predetermined path schedule in the determination control device 60.

  First, the determination control device 60 determines whether or not the edge profile on the exit side of the final stand 100 according to the existing path schedule is edge-up (step S110). When it is determined that the edge is up, the process proceeds to step S120. When it is not determined that the edge is up, the process proceeds to step S130.

  When it is determined in step S110 that the edge is up, the determination control device 60 calculates the line load at the final stand 100 from the relationship between the plate crown and the edge up that is obtained in advance and stored in the storage unit 80. After adjusting, the process returns to S110 to determine again whether the edge is up or not, and a condition that does not cause the edge up is obtained.

  After it is determined in step S110 that the edge is not up, the determination control device 60 determines that the plate shape is within an allowable range and the crown of the final stand 100 is a predetermined value when the line load selected in step S110 is used. It is determined whether or not the following is true (step S130). When it is determined that the plate shape is within the allowable range and the plate crown at the final stand 100 is less than or equal to the predetermined value, the processing is ended as a pass schedule in which the special roll profile control by the work roll vendor 140 is not performed. If not, the process proceeds to step S140.

Next, the determination control device 60 adjusts the work roll bending force of the work roll bender 140 in the final stand 100 based on the relationship between the plate crown and the edge profile stored in advance in the storage unit 80 as shown in FIG. (Step S140) .
Next, the determination control device 60 again determines whether or not the plate shape on the outlet side of the final stand 100 is within the allowable range and the plate crown on the final stand 100 is equal to or less than a predetermined value (step S150). If it is determined that the plate shape is within the allowable range and the plate crown on the final stand 100 is less than or equal to the predetermined value, the process ends. If it is determined that the plate crown is not less than the predetermined value, the process proceeds to step S160.

  When it is determined in step S150 that the plate shape is within the allowable range and the plate crown on the final stand 100 is not less than or equal to the predetermined value, the determination control device 60 determines that the finishing post side (initially F4 stand 40, step The adjustment of the work roll bending force by the work roll benders 44, 34, 24, and 14 is adjusted in order from the F3 stand 30 when the S160 is the second time, and the F2 stand 20 when the S160 is the second time (step S160). . That is, even if the plate shape on the exit side of the final stand 100 does not fall within the allowable range even in the stand before the final stand, or the plate crown on the exit side of the final stand does not reach the predetermined value, the work roll benders are sequentially moved further upstream. Adjust the bending force (plate shape control parameter). Thereafter, the process is returned to step S130 and a determination is made to find a solution in which the plate shape is within the allowable range and the plate crown is a predetermined value, the final pass schedule is determined, and the plate profile control is performed.

  Next, the effect of the present embodiment will be described.

  In the hot finishing tandem rolling mill 1 according to the first embodiment of the present invention described above, the line load and the plate shape obtained for the final stand 100 of the hot finishing tandem rolling mill 1 in the determination control device 60 of the control system 50. Based on the relationship between the crown and edge profile on the exit side of the final stand 100 with respect to the control parameters, the line load of the final stand 100 is adjusted so that the edge profile is within the allowable range, and the plate shape on the exit side of the final stand 100 is allowed. A predetermined pass schedule is determined by adjusting a plate shape control parameter of the final stand 100 so that the plate crown is within a predetermined value or less, and the rolling mill control device 70 determines the adjusted line load of the final stand 100. The plate shape of the final stand 100 is adjusted by controlling the reduction devices 15, 25, 35, 45, and 150 so as to obtain Control parameter is obtained to control a work roll bender 14,24,34,44,140.

  As a result, in hot finish tandem rolling, not only can the edge profile be controlled below a predetermined value, but also the plate shape can be controlled within a tolerance and below the predetermined value for the plate crown, and a good plate profile can be obtained. Can do.

  In addition, when determining the predetermined pass schedule, the determination control device 60 only adjusts the plate shape control parameter of the final stand 100 so that the plate shape on the exit side of the final stand 100 is not within the allowable range, or the plate crown is predetermined. If not less than the value, the upstream stand (F1 stands 10 to 10) is sequentially arranged from the final stand 100 toward the upstream side so that the plate shape at the final stand 100 is within the allowable range and the plate crown is below the predetermined value. In order to adjust the plate shape control parameters of the F4 stand 40), not only can the edge profile be controlled more reliably below the predetermined value, but also the plate shape should be controlled within the allowable range and the plate crown with the predetermined value or less. Can do.

  Furthermore, with respect to the existing pass schedule of the hot finishing tandem rolling mill 1, the line load of the final stand 100 is adjusted based on the relationship between the plate crown and the edge profile on the exit side of the final stand 100, and the existing pass schedule is adjusted. By adjusting the plate shape control parameters of the final stand 100 for the intermediate pass schedule with the adjusted line load, the edge profile can be controlled to a predetermined value or less stably and reliably, and the plate shape is within the allowable range. Thus, the plate crown can be controlled to a predetermined value or less.

  Further, when determining a predetermined pass schedule, a reduction amount of the final stand 100 that realizes a linear load on the final stand 100 is obtained, and the reduction schedule is set so that the plate shape is within an allowable range based on the reduction amount. By determining, it is possible to realize a constant plate crown ratio on the stand exit side, so that the plate shape is also improved, and a better plate profile can be provided.

  Further, the plate shape control parameter of the final stand 100 is the work roll bending force of the work roll bender 140, so that the work roll bender 140 that can be easily adjusted at the time of rolling is changed, and a good plate profile can be more easily obtained. Can be obtained.

<Example 2>
The plate | board profile control method and hot finishing tandem rolling mill of the hot finishing tandem rolling mill of Example 2 of this invention are demonstrated using FIG. 23 thru | or FIG. The same components as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

  As shown in FIG. 23, in the hot finishing tandem rolling mill 1A of the present embodiment, in addition to the hot finishing tandem rolling mill 1 of the first embodiment, a roll polishing device 160 is further provided around the work roll 120A of the F5 stand 100A. Has been placed.

  The roll polishing apparatus 160 is an apparatus that polishes the worn surface of the work roll 120A online or offline.

  In addition, in the determination control device 60A of the control system 50A, the line of the final stand 100 is set so that the edge profile is within an allowable range in consideration of the fact that the work roll 120A is being polished by the roll polishing device 160 disposed on the final stand 100A. A predetermined pass schedule is determined by adjusting the load.

  The rolling mill control device 70A performs rolling in each of the F1 stand 10 to F5 stand 100A based on the predetermined pass schedule determined by the determination control device 60A, and the work polishing 120A of the final stand 100A by the roll polishing device 160. The reduction devices 15, 25, 35, 45, 150, the work roll benders 14, 24, 34, 44, 140 and the roll polishing device 160 are controlled so as to be polished.

  Next, an example of the calculation result of the rolled steel sheet profile in the hot finish tandem rolling mill 1A will be described.

  Table 5 shows the calculation conditions of this example in which the thermal crown was compensated by installing the roll polishing device 160 on the final stand 100 and adjusting the wear crown, and the results are shown in FIG.

  In Table 5, the linear load at the final stand 100 is 6.7 kN / mm, and the thermal crown, wear crown, and initial crown of the work rolls 12, 22, 32, and 42 of the F1 stand 10 to F4 stand 40 are shown in FIG. As shown in Fig. 4, the thermal crown was considered to have a profile of -37.5 µm / rad (plate end 100 mm), the wear crown was -25 µm / rad (plate end 60 mm), and the initial crown was -140 µm / rad.

  Further, since the surface of the work roll 120A of the F5 stand 100 is constantly improved by the roll polishing device 160, the thermal crown, the wear crown, and the roll crown are set to zero. The conditions in Table 5 are defined as tandem rolling calculation conditions 4.

As shown in FIG. 25, by installing a roll polishing device 160 in the final stand 100A and compensating for the thermal crown, the work roll diameter, backup roll diameter, plate width, entry side plate thickness, exit side plate thickness, reduction amount, Even if the rolling reduction, rolling load, line load, work roll bending force, and cross angle conditions are the same as tandem rolling calculation condition 1, it can be seen that edge-up can be suppressed and the adjustment of the line load can be greatly reduced. I understood.

  Other configurations / operations are substantially the same configurations / operations as the plate profile control method of the hot finishing tandem rolling mill and the hot finishing tandem rolling mill 1 of Example 1 described above, and the details are omitted.

  The plate profile control method and hot finish tandem rolling mill of the hot finishing tandem rolling mill according to the second embodiment of the present invention also includes the plate profile control method and hot finishing tandem of the hot finishing tandem rolling mill according to the first embodiment described above. The same effect as a rolling mill can be obtained.

  Further, a roll polishing apparatus is arranged in the hot finish tandem rolling mill 1A, and the final stand 100A is used by using the roll polishing apparatus 160 while performing rolling at each stand (F1 stand 10 to F5 stand 100A) using a pass schedule. By rolling the work roll 120A while adjusting the wear crown on the surface of the work roll 120A, the rolling is performed while the surface shape of the work roll 120A is improved. The edge profile on the exit side can be controlled to a predetermined value. Therefore, the effect that the control range of each parameter including the line load at the final stand 100A is widened and the operation becomes easier can be obtained. In addition, since the surface of the work roll 120A is adjusted, it is possible to reduce the significant capital investment required for remodeling the work roll 120. By using the roll polishing device 160 only for the final stand 100A and not using the roll polishing device for the previous stand, it is possible to maintain a good plate profile while suppressing initial equipment costs and maintenance costs. Is particularly beneficial.

<Others>
In addition, this invention is not limited to said Example, Various modifications are included. The above-described embodiments have been described in detail for easy understanding of the present invention, and are not necessarily limited to those having all the configurations described.

DESCRIPTION OF SYMBOLS 1,1A ... Hot finishing tandem rolling mill 10 ... F1 stand 20 ... F2 stand 30 ... F3 stand 40 ... F4 stand 12, 22, 32, 42 ... Work rolls 13, 23, 33, 43 ... Backup rolls 14, 24, 34, 44 ... Work roll bender (plate shape control actuator)
15, 25, 35, 45 ... reduction device 50, 50A ... control system 60, 60A ... determination control device 70, 70A ... rolling mill control device 80 ... storage unit 100, 100A ... F5 stand (final stand)
110 ... Hot rolled material 120, 120A ... Work roll 130 ... Backup roll 140, ... Work roll bender (plate shape control actuator)
150: Reduction device 160 ... Roll polishing device

Claims (10)

In the plate profile control method of a hot finishing tandem rolling mill having a plurality of stands,
Based on the relationship between the line crown and the edge up or edge drop on the exit side of the final stand with respect to the line load and the flatness control parameter obtained for the final stand of the hot finishing tandem rolling mill, the edge up or Adjust the line load of the last stand so that the edge drop is within the allowable range,
Adjusting the flatness control parameter of the final stand so that the flatness on the exit side of the final stand is within an allowable range and the plate crown is equal to or less than a predetermined value;
A plate profile control method for a hot finishing tandem rolling mill, characterized in that the pass schedule of the final stand is adjusted based on the adjusted line load and flatness control parameter of the final stand. In the plate profile control method of the hot finish tandem rolling mill according to claim 1,
Or flatness in the final stand delivery side only by adjusting the flatness control parameter of the final stand does not become an allowable range, the case where the final stand delivery in side strip crown does not become less than the predetermined value, the final The hot finish is characterized by adjusting the flatness control parameters of the upstream stand so that the flatness at the final stand is within an allowable range and the plate crown is below a predetermined value sequentially from the stand toward the upstream side. Sheet profile control method for tandem rolling mill. In the plate profile control method of the hot finish tandem rolling mill according to claim 1,
Hot finish tandem rolling characterized by determining a rolling amount of the final stand that realizes a linear load at the final stand, and determining a rolling schedule based on the rolling amount so that the flatness is within an allowable range. Machine plate profile control method. In the plate profile control method of the hot finish tandem rolling mill according to claim 1,
A plate profile control method for a hot finishing tandem rolling mill, wherein the work roll of the final stand is polished while rolling at each stand using the pass schedule. In the plate profile control method of the hot finish tandem rolling mill according to claim 1,
For the existing pass schedule of the hot finish tandem rolling mill, the line load of the final stand is adjusted based on the relationship between the plate crown and the edge up or edge drop on the final stand exit side,
The flat profile control parameter of the final stand is adjusted with respect to an intermediate pass schedule in which the line load of the existing pass schedule is adjusted. A plate profile control method for a hot finishing tandem rolling mill. In the plate profile control method of the hot finish tandem rolling mill according to claim 1,
The flatness control parameter of the final stand is a work roll bending force, a roll cross angle, and a roll shift amount of a work roll bender. A plate profile control method for a hot finish tandem rolling mill. In a hot finishing tandem rolling mill having a plurality of stands,
A reduction device and a plate shape control actuator provided in each of the plurality of stands;
A decision control device for determining a predetermined path schedule;
A rolling mill control device that controls the reduction device and the plate shape control actuator based on the predetermined pass schedule determined by the determination control device;
The determination control device is based on the relationship between the plate crown and the edge up or edge drop at the exit side of the final stand with respect to the line load and the flatness control parameter obtained for the final stand of the hot finish tandem rolling mill. Adjusting the line load of the final stand so that the edge up or the edge drop is within an allowable range, and the flatness on the exit side of the final stand is within the allowable range and the plate crown is equal to or less than a predetermined value. The predetermined pass schedule is determined by adjusting a flatness control parameter of the stand,
The rolling mill control device controls the reduction device so as to obtain the adjusted line load of the final stand, and controls the plate shape control actuator so as to obtain the adjusted flatness control parameter of the final stand. Features a hot finish tandem rolling mill. In the hot finish tandem rolling mill according to claim 7,
When determining the predetermined pass schedule, the determination control device determines whether the flatness on the final stand exit side is within an allowable range only by adjusting the flatness control parameter of the final stand, or the final stand exit side If the plate crown does not fall below a predetermined value, the upstream side of the final stand so that the flatness at the final stand is within the allowable range and the plate crown is below the predetermined value sequentially from the last stand to the upstream side. A hot finish tandem mill characterized by adjusting the flatness control parameters of the stand. In the hot finish tandem rolling mill according to claim 7,
When determining the predetermined pass schedule, the determination control device obtains a rolling amount of the final stand that realizes a linear load at the final stand, and the flatness is within an allowable range based on the rolling amount. A hot finish tandem rolling mill characterized by determining the reduction schedule as follows. In the hot finish tandem rolling mill according to claim 7,
A roll polishing device;
The rolling mill control device performs rolling at each of the plurality of stands based on the predetermined pass schedule, and the rolling device and the plate shape control actuator so as to polish the work roll of the final stand by the roll polishing device. And a hot polishing tandem rolling mill characterized by controlling the roll polishing apparatus.

Images